1. Technical Field
The present invention relates to speech recognition systems and, more particularly, to a method for reducing search complexity in a speech recognition system.
2. Discussion of Related Prior Art
A speech recognition system consists of the following three major components: an acoustic fast match; an acoustic detailed match; and a language model. The fast match is employed to construct a list of candidate words given the acoustic evidence and the language model is employed to similarly construct a list of candidate words given the word context. The list of candidate words are then ranked so that only the top ranking candidate words are processed by the more detailed, computationally expensive, and time consuming detailed match.
Since the fast match examines all the words in the vocabulary in order to construct the list of word candidates, the fast match represents one of the most computationally expensive components of the speech recognition system. Thus, it would be desirable and highly advantageous to provide a method for reducing the processing time of the fast match. Further, due to the more detailed evaluation performed by the detailed match, it would also be desirable and highly advantageous to provide a method for shortening the list of word candidates processed by the detailed match.